AlephJ Mimi! (Mini)

[Salas]

Occasional sensitivity to incoming cable differences (i.e. inductance & capacitance) is good to try avoid. Maybe those stoppers could safeguard. But you will see better after investigation.

 

[lykkedk]

Occasional sensitivity to incoming cable differences (i.e. inductance & capacitance) is good to try avoid. Maybe those stoppers could safeguard better. But you will see better after investigation.

Yes...

Looking at original AlephJ schm. there is no gate stoppers on jfet there.
But looking at the diyaudio store AlephJ schm. there are jumpers, where gatestoppers could be installed. So maybee someone experianced some weird things during proto?

Anyway i will solder-in some ~500ohm on both channels. Also the 0,47 sourceresistor, which was hot i will replace just in case (you never know)

Jesper.

 

[Zen Mod]

hot (output) source resistor ......... say that current is 1A

470mW is hot to touch

 

[didiet78]

Yes...

Looking at original AlephJ schm. there is no gate stoppers on jfet there.
But looking at the diyaudio store AlephJ schm. there are jumpers, where gatestoppers could be installed. So maybee someone experianced some weird things during proto?

Anyway i will solder-in some ~500ohm on both channels. Also the 0,47 sourceresistor, which was hot i will replace just in case (you never know)

Jesper.

I thing that jumpers sugested by ZM. Proto made by 6L6 after finalizing layout.

 

[lykkedk]

Dual mono AlephJ_Mimi!

Dual mono AlephJ_Mimi!

So far so good...

Did not add gate resistors yet, had to finish and tryout the Dual PSU
GND at output from PSU's are connected at terminal, and i expect connection to chassis from that point (maybee through CL60?)

Everythings seem's fine so far.

Jesper.

BTW. : Did not test strange cable yet (faulty?)

 

[lykkedk]

Slowly going to finish all Alu'/Cu' chassis

Hi here...

Hard work (but fun too)... AlephJ_Mimi! chassis is born
Faceplate will be black. Topcover will be made of wire-mess 3mm. plate.
I will make some special attachments to the IRFP's, so heat is transfered from both bottom of mosfet, but also from the top. This arrangement will be made from 20x20mm. Alu'.

Have a nice evening all.
Rgds; Jesper.

 

[Salas]

Nice metalwork

 

[lykkedk]

Nice metalwork

Thanks.

__________________
Didiet
Usb I2S + AK4490 / WM8805+ESS9023 / SDHC Card I2S audio player + AD1860

Didiet, can you show the DAC's (Or telll about them) you have got in youre signature ?

Jesper.

 

[Zen Mod]

copper inlets are for Sissies

 

[lykkedk]

copper inlets are for Sissies

Iam thinking about adding some fancy vdc/mA/VU whatever meters on faceplate

Any suggestions ?

 

[Zen Mod]

aliexpress is full with them

 

[lykkedk]

Hi.

I will try two of those. -Just for fun, but maybee it's cool.

Jesper.

 

[Salas]

They also need some drive/calibration circuit if Vu. Better used for showing the bias because small sized and V scale. Do they have lights?

 

[lykkedk]

They also need some drive/calibration circuit if Vu. Better used for showing the bias because small sized and V scale. Do they have lights?

Hi Salas...

I will let them show bias, as bias in in range 0f ~0.4 - 0.5vdc, so it's perfect for that. But i just dont know if i kill them, when i start up the Aleph, as bias is peaking for a short time around 1-2vdc...

Maybe i will make some arrangement's, so that they are engaged after few seconds (like speaker protection)... Or maybe an resistor in series for damping the peak a little? -Let's see, when i got them, how sensitive they are?

Regarding the light's, i couldent find any with 0-1vdc scale including the backlight, but hey they must be hackable... dont you think soo?

Jesper.

 

[Salas]

Could put some led inside using the drill I guess... Amber in color maybe.

Put clamping diodes across the meter to stop overvoltage?

 

[Zen Mod]

100K trimer in series , 10uF across poles

connect across lower Rsource , set , forget

if needed (depending of full scale current) , decrease trimpot , to have broader setting range

 

[lykkedk]

Thanks both

There is something to play with, when they arrive (within 1 months or so)

Meantime i still have lot's of work to do with chassis...

Jesper.

I am on google hahaha

https://www.google.com/search?client=ubuntu&channel=fs&q=alephj+mimi%27&ie=utf-8&oe=utf-8#channel=fs&q=alephj+mimi

 

[Bangla H]

hi Jesper.
I was still following your nice build.
For tuby project i have saved this vu meter.
VU Mètre Meter Rétro-éclairage Audio Niveau Amplificateur Haute Sensibilité | eBay

 

[lykkedk]

hi Jesper.
I was still following your nice build.
For tuby project i have saved this vu meter.
VU Mètre Meter Rétro-éclairage Audio Niveau Amplificateur Haute Sensibilité | eBay

Yes... i also found this, when i was surfing the ebay/alibaba and the 40 thieves

Anyway you need a driver of some sort for this VU i think, and i have bigger interesst in watching the bias; that's why i ended up with buying 0-1vdc scale one's.

I am sure i can figure out somehow to make light inside the panelmeters! I will for sure try...

Jesper.

 

[lykkedk]

So they came fast from China this time ...

A little hacking gave them some light now!

Nice weekend out-there!

Jesper.